The invention relates to a stainproofing agent for carpet, a method for stainproofing a carpet and stainproof-treated carpet.
A variety of stainproofing agents are proposed to impart water-repellency, oil-repellency and stainproof properties to textile (eg. carpet).
Japanese Examined Patent Publication No. 8606/1973 discloses that stainproof properties are imparted by treating fibers with a homopolymer obtained by polymerizing an ester of an unsaturated carboxylic acid having a perfluoroalkyl group at both ends. However, this homopolymer is insufficient in stainproof properties.
Japanese Examined Patent Publication No. 3767/1976 discloses that stainproof properties are imparted to fibers by treating the fibers with a polymer obtained by polymerizing (i) an ester of maleic or fumaric acid having a perfluoroalkyl group at one end and an aliphatic or aromatic group having no fluorine atom at the other end with (ii) the other polymerizable unsaturated compound. Since one end of the ester of maleic or fumaric acid has no fluorine atom, its polymerizablity is good. However, this polymer is insufficient in water- and oil-repellency and is also insufficient in stainproof properties.
U.S. Pat. No. 3,594,353 discloses that a water repellency and stainproof properties to oil are imparted to fibers by treating the fibers with a polymer obtained by homopolymerizing an ester of itaconic acid having a perfluoroalkyl group at both ends or one end or copolymerizing said ester with the other polymerizable unsaturated compound. However, this polymer is insufficient in water- and oil-repellency and stainproof properties.
None of stainproofing agents which have hitherto been proposed presently has sufficient water- and oil-repellency, stainproof properties and also cleaning durability.
Although a carpet treated by a conventional method to impart water-repellency, oil-repellency and stainproof properties thereto is better than untreated carpet in initial water-repellency, oil-repellency and stainproof properties, the properties are insufficient, and cleaning durability of the carpet is also insufficient.
It is an object of the invention to provide a carpet with excellent initial water-repellency and stainproof properties and also outstanding cleaning durability, a stainproofing agent for carpet, a method for stainproof treatment of carpet.
The inventors conducted extensive research to solve such problems and found that excellent water-repellency, stainproof properties and cleaning durability may be imparted to a carpet by treating the carpet with a stainproofing agent and a specific crosslinking agent, thus the invention has been accomplished.
Thus, the invention relates to a carpet to which stainproof properties and cleaning durability are imparted by treating the carpet with (i) a fluoroalkyl-containing compound and (ii) a triazine ring-containing crosslinking agent, a stainproofing agent and a method for stainproof treatment of a carpet.
Stainproof degree of carpet of the invention maintains at least 30% after cleaning of 3 times, preferably 5 times, more preferably 10 times, further preferably 15 times, in particular 20 times.,
The fluorine-containing stainproofing agent 6 comprising a fluoroalkyl group (hereinafter referred to as xe2x80x9cRfxe2x80x9d) containing compound is not specifically limited to, but includes known compounds.
Examples of the fluorine-containing stainproofing agent comprising Rf group-containing compound are:
UNIDYNE TG-3010, TG-3020, TG-3040, TG-3510, TG-3520, TG-3710, TG-3720, TG-3711, TG-452, TG-452A, TG-930, TG-232 (DAIKIN Industries Ltd.);
SCOTCHGUARD FX-1367F, FX-1373M, FX-1355, FC-393, FC-367, FC-369, FC-398, FC-399 (Minnesota Mining and Manufacturing Co.);
ZONYL FCC, 8779, AFC, NRD-372, N-140, N-119 (E.I. du Pont de Nemours and Company);
ASAHIGUARD AG-820, AG-850, AG-923 (ASAHI GLASS CO., LTD.);
NUVA-FT, FTA (HOECHST AG); and
CRS-7 (NIKKA KAGAKU).
Specifically, the fluorine-containing stainproofing agent includes fluoroalkyl-containing maleic acid diester copolymer, fluoroalkyl-containing adipic acid diester compound and fluoroalkyl-containing urethane compound as shown below.
(1) Fluoroalkyl-containing Maleic Acid Diester Copolymer 
(2) Fluoroalkyl-containing Adipic Acid Diester Compound 
(3) Fluoroalkyl-containing Urethane Compound 
wherein Rf represents CnF2+1 (n is an integer of 5 to 21).
The amount of fluorine atom in solid content of stainproofing agent preferably ranges from 50 to 10,000 ppm based on the unit weight of carpet pile. Less than 50 ppm of the amount of fluorine atom results in insufficient stainproof properties. More than 10,000 of the amount of fluorine atom does not greatly improve stainproof properties.
The triazine ring-containing compound of the invention represented by formula (1) improves an adhesion property between said fluorine-containing stainproofing agent comprising Rf-containing compound and carpet pile, and also hardens coating: 
wherein R1 to R6 are the same or different, and represent xe2x80x94H, xe2x80x94OH, xe2x80x94CH2OCH3, xe2x80x94CH2OH, xe2x80x94CH2CH2OH, xe2x80x94CH2CH2CH2OH, or xe2x80x94CH2OC2H5, preferably xe2x80x94CH2OH.
As crosslinking agent represented by formula (1), trimethylolmelamine and hexamethylolmelamine are particularly preferable. Example of commercial name of the crosslinking agent is SUMITEX RESIN M-3 (trimethylolmelamine; SUMITOMO CHEMICAL Co. LTD.).
Coating mass of the triazine ring-containing compound preferably ranges from 0.01 to 1.0% by weight based on the unit weight of carpet. When coating mass is less than 0.01% by weight, cleaning durability is insufficient. When coating mass is more than 1.0% by weight, cleaning durability is not improved but results in hard feeling, thereby not preferable.
Catalyst is preferably added to the triazine ring-containing compound to accelerate a reaction. Examples of catalyst are formic acid, acetic acid and like organic carboxylic acids; organic carboxylates between the organic carboxylic acids and ammonium, sodium, potassium, etc.; sulfuric acid, persulfuric acid, hydrochloric acid, phosphoric acid, nitric acid and like inorganic acids; inorganic acid salts between the inorganic acids and ammonium, sodium, potassium, magnesium, zinc, aluminum, iron, etc. The amount of catalyst is not specifically limited to, but usually 5-100% by weight based on the amount of triazine ring-containing compound.
The stainproofing agent for carpet may be in the form of aqueous dispersion or solution in a solvent.
The stainproofing agent of the present invention can be applied by any method according to the kind of the material to be treated. For example, there can be used a method for applying the agent of the invention on the surface of material to be treated, using a known application procedure such as immersion, coating, etc., followed by drying. Furthermore, the stainproofing agent of the present invention may further comprise additives and a crosslinking agent other than said crosslinking agent. For example, polymethyl methacrylate/ethyl methacrylate (P-MMA/EMA) and like polymer, additives such as insect repellents, flame retardants, antistatic agents, dye fixing agents, wrinkle inhibitors, softeners and stain block agents which inhibit adhesion of acid dye may be appropriately added.
The material to be treated with the stainproofing agent of the present invention is preferably a textile, in particular, a carpet. Examples of the textile are animal-origin natural fibers such as cotton, hemp, wool, silk, etc.; synthetic fibers such as polyamide (nylon), polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride, polypropylene, etc.; semisynthetic fibers such as rayon, cellulose acetate, etc.; inorganic fibers such as glass fibers, carbon fibers, asbestos fibers, etc.; and a mixture of these fibers. Preferable fibers are polyamide (nylon), polyester, polyvinyl alcohol, polyacrylonitrile, polyvinyl chloride, polypropylene and like synthetic fibers, rayon, cellulose acetate and like semisynthetic fibers or a mixture thereof. The textile may be in any form such as a fiber, a yarn, a cloth and the like. When a carpet is treated with the stainproofing agent of the present invention, the carpet may be formed after treating fibers or yarns with the stainproofing agent. Alternatively, the formed carpet may be treated with the stainproofing agent.
The carpet of the invention may be pre-treated with stain block agent before stainproof treatment. Examples of stain block agent are generally a poly(meth)acrylic acid and a sulphonic acid-containing phenol/formaldehyde condensation product, specifically FX-668F (Minnesota Mining and Manufacturing Co.), SR-300 (E.I.du Pont de Nemours and Company). The stain block agent is preferably used in a sufficient amount which allow 0.05-10% by weight of active ingredient based on the weight of carpet to be adhered on carpet. Stain block agent may be applied according to a usual treatment process such as hot air treatment, steam treatment, boiled water treatment, etc.
The stainproofing agent of the invention may further comprises PEG and/or a copolymer comprising
(1) at least one selected from polyoxyethylene chain-containing acrylate and methacrylate; and
(2) at least one reactive monomer selected from glycerol methacrylate and glycidyl methacrylate).
The copolymer or PEG may be used in an amount of 1-50% by weight, preferably 2-20% by weight based on the solid content of repellant.
Color of carpet to be treated includes blue.
With respect to color of carpet,
L=40 to 80, preferably L=40 to 60;
a=+0.1 to xe2x88x920.8, preferably a=xe2x88x920.1 to xe2x88x920.6;
b=xe2x88x9213 to xe2x88x9225, preferably b=xe2x88x9217 to xe2x88x9221.
The carpet of the invention maintains a stainproof degree during resoiling of at least 20%, preferably at least 30% after one cycle of contamination, cleaning and recontamination.